Module Regression Ledger When to Activate - The repository has at least three interdependent modules, or a previous change to A has broken B. - A change modifies a module's externally observable behavior and must prove both that module and downstream consumers still work. - The project already has executable tests or reconciliation commands that should be organized by dependency. Anti-Patterns - Creating a regression ledger for a small repository with no cross-module dependencies. - Guessing dependencies manually or treating one scan as permanent truth. - Replacing executable acceptance-comma…